fix: prevent asset conflicts between React and Grid.js versions

Add coexistence checks to all enqueue methods to prevent loading
both React and Grid.js assets simultaneously.

Changes:
- ReactAdmin.php: Only enqueue React assets when ?react=1
- Init.php: Skip Grid.js when React active on admin pages
- Form.php, Coupon.php, Access.php: Restore classic assets when ?react=0
- Customer.php, Product.php, License.php: Add coexistence checks

Now the toggle between Classic and React versions works correctly.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

node_modules/framer-motion/dist/es/value/utils/resolve-motion-value.mjs

@@ -0,0 +1,16 @@
+import { isCustomValue } from '../../utils/resolve-value.mjs';
+import { isMotionValue } from './is-motion-value.mjs';
+
+/**
+ * If the provided value is a MotionValue, this returns the actual value, otherwise just the value itself
+ *
+ * TODO: Remove and move to library
+ */
+function resolveMotionValue(value) {
+    const unwrappedValue = isMotionValue(value) ? value.get() : value;
+    return isCustomValue(unwrappedValue)
+        ? unwrappedValue.toValue()
+        : unwrappedValue;
+}
+
+export { resolveMotionValue };